1. Field of the Invention
This invention relates to the oxidation of chlorinated organic compounds to recover chlorine values.
2. Summary of the Prior Art
Producers of highly useful chlorinated organic compounds such as perchloroethylene, carbon tetrachloride, chloroprene, and vinyl chloride are faced with serious disposal problems with respect to the undesirable chlorinated organic by-products that are formed in the reactions. Processes employing chlorine-containing compounds as intermediates, such as making propylene oxide by the chlorohydrin route, also produce unwanted by-products. By-products which may be formed singularly or in various combinations include materials such as hexachloroethane, hexachlorobutadiene, hexachlorobenzene, and various C.sub.3 and C.sub.4 chlorinated organic compound mixtures. A typical disposal method for the undesirable chlorinated aromatic by-products currently consists primarily of terrestrial burial. Also used are ocean discharge, open pit burning, drum burial, and deep-well disposal. These methods, however, have engendered serious criticism as being dangerous to the environment. In addition, these methods may be economically unattractive because the cost of the undesirable chlorinated by-products being disposed is not diminished at least in part by recovery of some material of significant economic worth. Incineration of the undesirable chlorinated by-products by means of high performance burners or furnaces has also been proposed. Such proposal is disclosed, for example, in an article in Chemical Week, Apr. 19, 1972, pages 37 and 38, and French Pat. No. 1,326,053. Also British Pat. No. 1,002,008 discloses a process for recovering the chlorine from chlorocarbon residues, such as produced in the above-mentioned processes, by burning these residues at an elevated temperature with oxygen or free oxygen containing gases. This process, however, requires the utilization of temperatures between about 700.degree. and 1300.degree. C. These high temperatures require special equipment that is stable at such temperatures and will resist corrosion by the chlorine, HCl and water produced, thus increasing capital expenditures and maintenance costs. Similarly, U.S. Pat. No. 3,548,016 discloses an involved multistep process for recovering chlorine values from certain chlorinated hydrocarbons by first burning, then reacting the combustion effluent with a salt mixture of cuprous chloride and copper oxychloride, and then reacting the resulting salt mixture with chlorinated hydrocarbon.